Flora of China 5: 395-396. 2003. 31. HALOXYLON Bunge, Mém. Acad. Imp. Sci. St.-Pétersbourg Divers Savans 7: 468. 1851. 琐琐属 suo suo shu Shrubs or trees, glabrous, or cottony in leaf axils. Stem erect, much branched; older branches terete, annual ones green or blue- green, pointed. Leaves opposite, reduced to scales or nearly absent, bases united, apex obtuse or with a short awn. Flowers solitary in leaf axils, bisexual, with 2 bractlets. Perianth segments 5, free, papery or dry membranous, abaxially with a distal, transverse wing in fruit, adaxially concave, base usually arachnoid; wing horizontal, membranous, longitudinally veined. Disk cupular. Stamens 5, inserted on disk; anthers elliptic, without an appendage. Ovary base sunken into disk; style very short; stigmas 2–5. Utricle hemispheric, apically slightly concave; pericarp fleshy, adnate to seed. Seed horizontal; embryo green, spiral; perisperm absent. About 11 species: from the Mediterranean region to C Asia; two species in China. 1a. Leaves appressed to stem, triangular, apex awned ....................................................................................................... 1. H. persicum 1b. Leaves slightly spreading, broadly triangular, apex awnless .............................................................................. 2. H. ammodendron 1. Haloxylon persicum Bunge ex Boissier & Buhse in Nouv. 琐琐 suo suo Mém. Soc. Imp. Naturalistes Moscou 12: 189. 1860. Anabasis ammodendron C. A. Meyer in Ledebour, Fl. 白琐琐 bai suo suo Altaic. 1: 375. 1829; Arthrophytum ammodendron (C. A. Arthrophytum acutifolium (Minkwitz) Minkwitz; A. Meyer) Litvinov; A. ammodendron var. aphyllum Minkwitz; ammodendron (C. A. Meyer) Litvinov var. acutifolium Mink- Haloxylon aphyllum (Minkwitz) Iljin. witz; A. persicum (Bunge) Savicz-Ryczegorski. Trees small, 1–9 m tall. Trunk to 50 cm in diam. at ground Trees small, 1–7 m tall. Bark gray-white; wood hard, brit- level; bark gray-white; wood hard, brittle; older branches gray- tle; older branches gray-brown or light yellow-brown, usually brown or light yellow-brown, usually fissured annular; annual fissured annular; annual branches pendulous, internodes 0.5–1.5 branches obliquely spreading or pendulous, long, thin, inter- cm × ca. 1.5 mm. Leaves appressed to branch, scale-like, tri- nodes 0.4–1.2 cm × ca. 1.5 mm. Leaves slightly spreading, angular, apex awned; leaf axil cottony. Flowers borne on dwarf, scale-like, broadly triangular, apex obtuse, awnless; leaf axil lateral spurs of previous year’s branches; bractlets navicular, cottony. Flowers borne on dwarf, lateral spurs of previous ovate, equaling perianth, margin membranous. Perianth seg- year’s branches; bractlets navicular, broadly ovate, nearly ments ovate, apex obtuse or subacute; abaxial wing borne 1/4 of equaling perianth, margin membranous. Perianth segments ob- distance from apex, light yellow, flabellate or suborbicular, 4–7 long, portion above abaxial wing slightly incurved, surrounding mm wide, obscurely veined, base broadly cuneate to rounded, margin repand or subentire. Disk obscure. Utricle light yellow- utricle, apex obtuse; abaxial wing borne ca. 1/3 of distance from brown; pericarp not adnate to seed. Seed ca. 2.5 mm in diam.; apex, obliquely spreading or horizontal, kidney-shaped to embryo spiral, abaxially convex, turbinate, adaxially plane. Fl. suborbicular, 5–8 mm wide, base cordate to cuneate, margin May–Jun, fr. Sep–Oct. undulate or erose. Disk obscure. Utricle yellow-brown; pericarp not adnate to seed. Seed black, ca. 2.5 mm in diam.; embryo Dunes. N Xinjiang [NE Africa, SC and SW Asia]. dark green, spiral, abaxially convex, turbinate, adaxially plane. This species is very useful for sand-binding and afforestation. It Fl. May–Jul, fr. Sep–Oct. has been introduced to sand areas of Gansu, Nei Mongol, and Ningxia for this purpose. Dunes, saline-alkaline deserts, sandy places on riversides. W 2. Haloxylon ammodendron (C. A. Meyer) Bunge in Lede- Gansu, Nei Mongol, NW Ningxia, N Qinghai, Xinjiang [Mongolia; C bour, Fl. Ross. 3: 820. 1851. Asia]. Flora of China 5: 395-396. 2003..